Nitrogen - containing organic compounds and process for their preparation



Patented pr. 9, 1940 PATENT OFFICE NITROGEN CONTAINING ORGANIC COM- POUNDS AND PROCESS FOR THEIR PREP- ABA'I'ION Adrianus Johannes van Peski, Amsterdam, Netherlands, assignor to Shell Development Company,- San Francisco, Calif., a corporation 01' Delaware NoDrawing. Application July 2, 1938, Serial N0. 217,278. In Great Britain July 8, 1937 16 Claims.

This invention relates to a process for the'production of valuable imidines and soy] amidines and/or the tautomers of such compounds, which process comprises reacting an aliphatic amidine,

5 or a compound capable of yielding an aliphatic amidine under the conditions 01 execution of the process, with a suitable iminating agent or acylating agent.

The invention also relates to novel and valuable imidines and acylamidines, and their tautomers, as well as metal derivatives of such compounds, I which compounds are adapted to a variety of commercial uses. The novel compounds are usein] raw materials in the production of pharmaceutical preparations, as assistants in the textile industry, as colorants, as agents and components in preparations for destroying noxious organisms, as agents for improving the quality of lubricating compositions, as agents for improving the properties of motor fuels with respect to their anti-knock value, and they may be advantageously employed, alone or in admixture with other agents, for still other purposes.

The imidines and acyl amidines prepared in accordance with the process of the invention may be represented by the general formula:

Iii-0 x or tautomeric forms thereof wherein R: represents hydrogen or an aliphatic or cyoloaliphatic radical and R1 and Rs are the same or diflerent and represent hydrogen atoms, or alkyl radicals, aralkyl radicals, cycle-aliphatic radicals or aryl radicals which may or may not be further substituted, and wherein X represents an oxygen atom or the radical NR4. When X represents the 50 divalent organic radical, or R2 and B: may be linked together by one or more intervening carbon atoms and/or other atoms or radicals.

The aliphatic amidines which are reacted with an iminating agent or an acylating agent in accordance with the process of the invention may be of open-chain or cyclic character and contain one or a plurality'foi characteristic amidine groups The simpler amidines suitable Ior use in the execution of the invention may be represented by the general formula R(IJ=N R1 NH:

in the appended claims to designate a group of agents the members ofwhich are capable of reacting with amidines under the conditions of execution of the process of the invention to introduce into the structure or the amidine, by replacement of a hydrogen atom of the -NH: group, at least one group. The iminating agents maybe 01' openacetonitrile, propionitrile, the butyronitriles, ben-'- zonitrile and the like. The imino-halides may be represented by the general formula wherein R and R1 are the same or diilerent and represent hydrogen atoms or alkyl, aralkyl, cycloaliphatic or aryl radicals which may or may not be iurther substituted, and Hal represents a halogen atom. The imino ethers may be represented by the same general formula wherein -Hal is replaced by the group OR: wherein R: represents an alkyl, aralkyl, cycloaliphatic or aryl radical which may be the same or diii'erent, than R. Representative imino-halides are: acetchlorimide, propionchlorimide, the butyrchlorimides, benzochlorimide, pivalyl allyl chlorimide, etc. Representative imino ethers are CH3C(NH) OCH3, C2HC (NH) OCH3, Cal-17C (NH) OCzHs, CeHsC OCH:

and the like.

The reaction whereby an aliphatic amidine is reacted with an iminating agent in accordance with the process of the invention to yield an imidine may be represented by the, following equation illustrating the reaction of a simple amidine with a simple imino-halide (tautomeric iorms omitted for the sake of clarity) group. The acylating agents may be of openchain or cyclic character. Representative suitable sub-groups of acylating agents are the carboxylic acids, the carboxylic acid anhydrides, the carboxylic' acid halides, the ketenes, etc. Suitable carboxylic acids are formic, acetic, 'propionic,

butyric, isobutyric, acrylic, methacrylic, benzoic,

cinnamic, oxalic, phthalic, succinic, maleic, pyruvic and the like and their homologues, analogues and suitable substitution products. Sultable carboxylic acid, anhydrides and carboxylic acid halides are the anhydrides and acid halides, respectively, of the above named as well as other carboxylic acids. Suitable ketenes are ketene CH2=CO, methyl ketene CH3CH=CO, phenyl ketene CcH5CH=CO, diphenyl ketene (CsHs) 2C=CO and the like and their homologues, analogues and suitable substitution products.

The reaction whereby an aliphatic amidine is reacted with an acylating agent in accordance with the process of the invention to yield an acyl amidine may be represented by the following equation illustrating the reaction of a simple amidine with a carboxylic acid (tautomerlc forms or dispersing agents which may,'it' desired, be

advantageously employed are hydrocarbons and hydrocarbon mixtures such as benzene, hexane,

octane, gasoline, diisobutylene, etc. the alcohols such as ethanol, propanol, the butanols, etc. the etherssuch as ethyl ether, ethyl propyl ether, diisopropyl ether and the like,

In general, the process is advantageously executed at temperatures of from about 20 C. to about 150 C. Higher or lower temperatures may be used when necessary or desirable. The process is in general conveniently executed at about atmospheric pressure. or subatmospherlc pressures may be used when necessary or desired: The process is usually executed with the reactants in the liquid phase.

The imidines and acyl amidines may be recovered from the reaction mixture in any suitable manner, the specific mode of recovery being adapted to the nature of the product. Suitable modes of recovery include extraction, distillation, etc.

The following specific examples illustrate a suitable mode of executing the process of the invention. It is to be understood that the examples are for illustrative purposes, and that the invention is not to be regarded as limited to the specific reactants, conditions, or mode of operation therein described.

Example I About 15.5 parts by weight of pivalyl-allylimide chloride I ((CH;);CC=N -CH -CH=CH,)

which may be prepared by reacting pivalyl chloride with allyl amine and treating the resulting pivalyl-allyl-amide with phosphorus pentachloride to form pivalyl-allyl-amide chloride which loses HCl spontaneouslygiving the desired pivalyl-allyl-imide chloride, were dissolved in about parts by weight of benzene. This solution was added slowly to a cooled solution consisting of about 8 parts by weight of butyramidine dis- Superatmospheric pressure The residue was dissolved in methyl ethyl ketone,

and the product recovered in purified form by crystallization therefrom Analysis of the prod- This novel compound maybe designated as (allyl-pivalo) -butyr-imidine hydrochloride.

Example II To 30.4 grams of ethyl acetamidine dissolved in about 150 cubic centimeters of absolute ether were added 14.3 grams of powdered sodium hydroxide. Then 37.7 grams of butyryl chloride dissolved in 80 cubic centimeters of absolute ether was added dropwise to the mixture. The temperature was kept at about 25 C. during the reaction by cooling. The sodium chloride precipitate formed was filtered of! and the ether. evaporated. The remaining product was then ira'ctionally distilled in vacuo. The yield of butyryi ethyl acetamidine,

boiling point 7849? C. under'0.25 mm. of mercury, was 37.0 grams.

Example III By reacting acetyl chloride with methyl butyramidine /NH (CiHr-C NHCH:

Non

Example IV To 13.7 grams of allyl butyramidine dissolved in cubic centimeters of benzene was slowly added drop by drop, 17.3 grams of pivalyl-allylimide chloride dissolved in cubic centimeters of benzene. The hydrochloride of allyl pivalo allyl butyrimidine was formed with evolution of heat but the temperature was kept at about 0 C.

by cooling. The reaction mixture was shaken for several hours at room temperature. The product was then recovered in a substantially pure state by evaporation of the solvent in vacuo.

As is shown in the examples, when one of the products of the reaction is a hydrogen halide, or when the reaction is effected in the presence of a hydrogen halide, the imidine or acyl amidine.

may be obtained in the form of its hydrohalide.

Metal derivatives of the compounds of my invention may be prepared by reacting them with suitable compounds of the desired metal. Thus, for example, sodium compounds of the products produced in Examples II and III have been prepared by reaction of the acyl amidines with sodium ethylate.

salt, an amount of sodium ethylate must of course be used sumcient to first liberate the imidine and to convert it to the sodium salt.

The novel imidines and acyl amidines, and the tautomers of these compounds, prepared in accordance with the process of the invention are all nitrogen-containing organic compounds wherein at least one carbon atom is linked by a double bond to one nitrogen atom and by a single bond to another nitrogen atom. The imidines proper contain two carbon atoms linked by double bonds to separate nitrogen atoms and by single bonds to the same imino radical. In the tautomeric form of the imidines, one carbon atom is linked by a double bond to a nitrogen atom which in turn is linked by a single bond to a carbon atom, each of said carbon atoms being linked, respectively, to other nitrogen atoms, the former by a single bond, and the latter by a double bond. In another form which the imidines may take is characterized by the presence of two carbon atoms linked by double bonds to separate nitrogen atoms and by singlebonds to a nitrogen atom which is linked to a third carbon atom. Using the same symbols as in the general formula, the various forms which the imidines may take may be represented as follows:

The acyl amidines proper contain an imino radical linked by a single bond to a carbon atom which in turn is linked by a double bond to a nitrogen atom, the other bond of the imino radical being linked to the carbon atomof a carbonyl group. The acyl amidine tautomers contain a nitrogen atom linked by a double bond to a carbon atom which inturn is linked by a single bond to another nitrogen atom, and by a single bond to the carbon atom of a carbonyl group. The acyl amidines may also be characterized by the presence in the molecule of a nitrogen atom directly linked to three carbon atoms one of v which is linked by a double bond to another nitrogen atom and another of which is the carbon atom of a carbonyl group. These structures may be represented by the following formulae:

or corresponding enol forms.

The invention contemplates the metal derivatives of the imidines, acyl amidines and their tautomers herein described. One or more of the hydrogen atoms which are linked to nitrogen atoms or carbon atoms in the imidines, acyl amidines and their tautomers may be replaced by suitable monovalent or polyvalent metal or metal-containing radicals. Representative metal derivatives are those containing silver, copper, zinc, nickel, iron, lead and the like metals.

A number of copper compounds from various products obtained according to the present case have been tested on their anti-knock action. The copper compounds were added to a parafflnous straight-run gasoline having an octane,

number of 40, and the following results were obtained: I

Percent by 0m Copper compound oiweight 5 in. gasoline number 1) Acetyl ethyl butyramidine 0.08 57. 2 Butyryl allyl butyramidine 0. 10 50. 3 Butyryl ethyl acetamidine 0.075 56 4 Propionyl methyl acetamidine. '0. 10 61. 5) Butyryl butyramidine 0.07 45. 6) Allyl pivalo allylbutyramidlne 0.05 43.

The corresponding cobalt compounds give greater increases in octane number under similar conditions. Copper derivatives of 'cyclic compounds of the type of acetyl cyclohexylacetamidine, N-phenyl-N-acetyl-benzamidine. and the like are also anti-knock agents.

My invention provides a new source fora wide the following example. I

Example V Hydrochloric acid gas is introduced into butyronitrile at up to the point of saturation, after .which the solution is left over for some weeks in a closed vessel at room temperature. Subsequently the unconverted hydrochloric acid and butyronitrile are vaporized, whereupon the remainder crystallizes out. The presumable structure of this substance is:

NELHCI OzHLC C1551 imide chloride of butyryl butyramidino Na NlELHCl (B T-C C1+HC1 CaH1.C C1

=C I N=C HG] salt Of the imide chloride Upon careful reaction of diluted lye the molecule of hydrochloric acid is eliminated again,

whilst at the same time the other chlorine atom is replaced by a hydroxyl group. 'I'hesubstance thus obtained is the tautomeric form of the butyryl butyramidine: A

N=o a Since the actionof water'may even go further (the =NH group being replaced by =0, so that dibutyramide is formed), the hydrolysis. is car=- -ried out in the presence of an organic solvent immiscible with water, copper acetate being added immediately after the addition of lye.

butyramidine is formed, which very readily dissolves in organic solvents (such as pentane) and is thus withdrawn from the decomposing eflect of the water. Finally, by recrystallization from pentane at a low temperature, the copper compound is obtained in the pure state, melting pt.

It will thus be evident that in accordance with the process of my invention imidines and acyl amidines or their tautom eric forms or derivatives thereof may be produced by causing nitriles,

Inv this way the copper compound of the butyryl including aliphatic and cyclic. particularly cycloaliphatic nitriles or substances derived therefrom such, for example, as amidines, to react with suitable iminating agents and the like.

While I have described my invention in a detailed manner and illustrated suitable modes of executing the same, it is to be understood that modifications may be made and that no limitations other than those imposed by the scope of the appended claims are intended.

I claim as my invention:

1. A process for the production of useful nitrogen-containing organic compounds wherein at least one carbon atom is linked by a double bond to one nitrogen atom and by a single bond to another nitrogen atom which comprises reacting substantially equimolecular quantities of an aliphatic amidine and an organic compound of the class consisting of the iminating agents which react with the aliphatic amidine to replace a hydrogen atom of the NH: group thereof by a group and the acylating agents which react with the aliphatic amidine to replace a hydrogen atom 01 the --NI-I= group thereof by a group and the acylating agents which react with the aliphatic amidine to replace a hydrogen atom of the NH: group thereof by a group, the reaction being effected in the liquid phase in the'presence of a substantially inert liquid solvent.

3. A process for the production of useful nitrogen-containing organic compounds wherein at least one carbon atom is linked by a double bond to one nitrogen atom and by a single bond to another nitrogen atom which comprises reacting an aliphatic amidine with a substantially equimolecular quantity of an organic compound of the class consisting of the iminating agents which react with the aliphatic amidine vto replace a hydrogen atom of the -NH2 group there of by a group and the acylating agents which react with the aliphatic amidine to replace a hydrogen atom of the -NH2 group thereof by a group, the reaction being effected in the liquid phase at a temperature of from 20 C. to 150 C'.

4. A process for the production of an imidine which comprises reacting an aliphatic amidine with an iminating agent which reacts with the aliphatic amidine to replace a hydrogen atom of the NH2 group thereof by a t=NH group.

5. A process for the production of an acyl amidine which comprises reacting an aliphatic amidine with a substantially equimolecular quantity of an acylating agent which reacts with the aliphatic amidine to rep1ace a hydrogen atom of the NH: group thereof by a 6. A process for the production of an imidine which comprises reacting an aliphatic amidine with an iminating agent of the class consisting of the organic nitriles, imino-halides and iminoethers.

7. A process for the production of an imidine which comprises reacting an aliphatic amidine with an imino-halide.

8. A process. for the production of an acyl amidine which comprises reacting an aliphatic amidine with a substantially equimolecular quantity of an acetylating agent of the class consisting of the carboxylic acids, the carboxylic acid anhydrides, the carboxylic acid halides and the ketenes.

9. A process for the production of an acyl amidine which comprises reacting an aliphatic amidine with a substantially equimolecular quantity of a. carboxylic acid.

10. A process for the production of (allylpivalo) -butyr-imidine hydrochloride which comprises reacting butyramidine with pivalyl-allylimino chloride.

11. A novel class of organic compounds consisting of the nitrogen-containing organic compounds possessing an imino radical linked by single bonds to two carbon atoms one of which is linked by a single bond to an aliphatic radical and by a double bond to a nitrogen atom which is linked by a single bond to a hydrocarbon radical and the other of which said carbon atoms is linked by a double bond to an oxygen atom and wherein R1 and R3 each represents a hydrocarbon radical and R2 represents a substituent of the group consisting of the hydrogen atom and aliphatic radicals, and the tautomers of said acyl amides.

13. A class of novel imidine compounds consisting of the compound of the formula:

and the hydrohalides of said compound.

14. A class of novel unsaturated imidines consisting of the unsaturated imidines of the general formula:

wherein R1, R2 and Rs represent hydrocarbon radicals at least one of which is an aliphatic unsaturated hydrocarbon radical, the tautomers of said unsaturated imidines, the hydrohalides of said unsaturated imidines, and the heavy metal derivatives of said unsaturated imidines.

15. The heavy metal derivatives of compounds selected from the group consisting of the acyl amidines of the general formula wherein R1 and R3 each represents a hydrocarbon radical and R2 represents a substituent of the group consisting of the hydrogen atom and aliphatic radicals, and of the tautomers of said acyl amidines.

lfirThe copper salts of acyl amidines having the general formula wherein R1 and R3 each represents a hydrocarbon radical and R2 represents a substituent of the group of the hydrogen atom and aliphatic radicals, and of the tautomers of said' acyl amidines.

ADRIANUS JOHANNES VAN PESm. 

